Mario M. Cuomo’s hate-hate relationship with “The Godfather” has been well documented. For four decades, he refused even to see any of the movies or, presumably, to read Mario Puzo’s book. He all but denied that the Mafia existed. And who could forget that unfortunate slip of the tongue during the 1992 presidential campaign, when Bill Clinton suggested that Mr. Cuomo, then the governor of New York, acted like a Mafioso?

But over the weekend, Mr. Cuomo, 81, did the unthinkable: he finally watched “The Godfather.”

And, somewhat grudgingly, he offered that “maybe this thing was a masterpiece.”

Mr. Cuomo’s change of heart was spurred by the 2013 Forum Film Festival at the Forum on Law, Culture and Society at Fordham Law School, when he finally accepted an offer long refused.

Indeed, he had turned down an invitation from Mayor John V. Lindsay when the film was released in 1972, maintaining his boycott until the night before Sunday’s forum. Nor, unlike another Italian-American politician, Rudolph W. Giuliani, the former mayor and United States attorney, did he typically play up the Mafia’s role in America.

In fact, when Paul Castellano, the mob boss, was executed in 1985 in front of Sparks Steak House in Manhattan, Mr. Cuomo urged reporters to refrain from invoking the word Mafia in reference to the hit. “Every time you say it, you suggest to people that organized crime is Italian,” he said. “It’s an ugly stereotype.”

“You’re telling me that Mafia is an organization,” he was quoted as saying, “and I’m telling you that’s a lot of baloney.”

On Sunday, though, he said yes, there was a Mafia, born of vicious invasions of Sicily. “They created an organization to fight those people who were intruders but they got out of hand and they moved here,” he said.

He added, though, that Italians and blacks were typically singled out for abuse in American movies and that those stereotypes had spilled over into politics. When he was first running for office, he recalled, “only 16 percent said they knew me.

“And 14 percent said they wouldn’t vote for me because of my relationship to bad criminals,” said Mr. Cuomo, who was governor from 1983 through 1994.

“When I didn’t run for president,” Mr. Cuomo later recalled, “there were two reasons people gave in their dark speculations: I must be in organized crime or have colon cancer. Nobody was saying I had a 28-year-old blond girlfriend.”

As for the film, Mr. Cuomo pronounced it “great, if you’re referring to artistry.” Still, he expressed dismay that films like “The Godfather” and television programs like “The Sopranos” delivered a “horrible” message by stereotyping Italian-Americans for taking the law into their own hands to seek revenge and sanctioning murder.

Prodded by the moderator, Prof. Thane Rosenbaum, and his fellow panelist, Larry King, Mr. Cuomo refused to draw a distinction between entertainment and what he considered the insidious immoral message conveyed by Mafia movies.

“You demean our system of law and order by saying if you want to get justice you mow down the bums,” Mr. Cuomo said.

Then why do so many people go see those movies? Mr. King asked.

“I don’t go,” Mr. Cuomo replied flatly, before softening his tone.

“I’m against the death penalty,” he added, “except for people who make bad movies.”